Field of the Invention
The present invention relates to novel subtilase variants exhibiting increased stability and/or. improved wash performance The variants of the invention are suitable for use in e.g. cleaning or detergent compositions, such as laundry detergent compositions and dish wash compositions, including automatic dish wash compositions. The present invention also relates to isolated DNA sequences encoding the variants, expression vectors, host cells, and methods for producing and using the variants of the invention.
Description of the Related Art
In the detergent industry, enzymes have for many decades been implemented in washing formulations. Enzymes used in such formulations comprise proteases, lipases, amylases, cellulases, mannosidases as well as other enzymes or mixtures thereof. Commercially the most important enzymes are proteases.
An increasing number of commercially used proteases are protein engineered variants of naturally occurring wild type proteases such as Everlase®, Relase®, Ovozyme®, Polarzyme®, Liquanase®, Liquanase Ultra® and Kannase® (Novozymes NS), Purafast®, Purafect OXP®, FN3®, FN4® and Excellase® (Genencor International, Inc.). Further, a number of variants are described in the art, such as in WO2004/041979 (Novozymes NS) which describes subtilase variants exhibiting alterations relative to the parent subtilase in e.g. wash performance, thermal stability, stability during wash or catalytic activity. The variants are suitable for use in e.g. cleaning or detergent compositions.
A number of useful subtilase variants have been described many of which have provided improved activity, stability, and or solubility in different detergents. For example, WO 2004/041979 describes variants comprising a substitution from a list of positions, including position 131, in combination with a modification in one or more additional positions.
However, various factors make further improvement of the proteases advantageous. The washing conditions such as temperature and pH changes over time and many stains are still difficult to completely remove under conventional washing conditions. Thus despite the intensive research in protease development there remains a need for new and improved proteases that have increased stability and/or an improved wash performance.